North Korea has long-range missiles capable of reaching targets in Japan and U.S. bases in Guam, Okinawa and the Japanese mainland. / KCNA via AP

by Staff research, USA TODAY

by Staff research, USA TODAY

April 27, 1965: Two North Korean MiG-17s attack a U.S reconnaissance plane above the Sea of Japan. The aircraft is damaged.

Jan. 17,1968: A unit of the North Korean army disguised as South Korean soldiers crosses the DMZ in an attempt to kill South Korean President Park Chung Hee. The assassins make it to Blue House, the official residence of the president, but are stopped in a firefight. Twenty-eight members of the unit are killed.

Jan. 23, 1968: The U.S. Navy ship the USS Pueblo is boarded and captured, along with its crew, by North Korean forces in the Sea of Japan in North Korean waters. One sailor is killed in the attack. The 83 other crewmembers are held until Dec. 23.

Oct. 30,1968: A wave of more than 100 North Korean commandos begins landing on the northeast shore of South Korea to wage a guerrilla war against the South Korean government. A total of 110 commandos and 20 South Koreans are killed.

April 15,1969: A U.S. reconnaissance plane is shot down off the North Korean coast, killing 31 Americans.

1970s

June 5,1970: North Korean patrol boats seize a South Korean broadcast vessel with 20 crew on board.

Feb. 15,1974: North Korea sinks two South Korean fishing boats.

Aug. 18, 1976: Two U.S. officers cutting down a tree in the DMZ are killed with axes by North Korean troops.

1980s

March 1980: Three North Koreans are killed trying to cross the Han River.

July 1981: Three North Koreans are killed trying to cross the Imjin River.

November 1984: Nine North Korean soldiers and one South Korean soldier are killed in firefight after a Soviet man tries to escape into South Korea.

1990s

May 1992: Three Northern soldiers in South Korean uniforms are killed in Cheolwon, Gangwon-do.

December 1994: North Koreans shoot down U.S. Army helicopter, killing one American.

May 1995: North Korean forces fire on a South Korean fishing boat, killing three.

May 1996: Seven North Korean soldiers cross into the DMZ but return after warning shots are fired.

April 1997: Five North Korean soldiers cross the DMZ in Cheolwon, Gangwon-do, and fire on South Korean positions.

June 1997: Three North Korean vessels cross into South Korean territorial waters and attack South Korean boats. A unit of North Korean soldiers crosses the DMZ and are turned back in a firefight.

June 1999: Several clashes between North and South Korean vessels take place in the Yellow Sea near the border between the two countries.

2000s

June 29, 2002: North Korea vessels attack a South Korea naval ship, killing four South Korean sailors and sinking the vessel.

July 17, 2003: North and South Korean forces exchange fire at the DMZ.

Oct. 9, 2006: North Korea conducts its first nuclear test, in violation of international agreements it has signed.

May 25, 2009: North Korea conducts a second nuclear test, in violation of a U.N.Security Council resolution.

Nov. 10, 2009: Naval vessels from North and South Korea exchange fire near the border.

2010s

March 26, 2010: North Korea sinks the South Korean naval vessel Cheonan with a torpedo in the Yellow Sea. Forty-six sailors are killed.

Nov. 23, 2010: North Korea fires artillery shells at South Korea's Greater Yeonpyeong island in the Yellow Sea. Two South Korean marines and two South Korean civilians are killed, and dozens of houses are destroyed.